<code>defaultRouter</code> - a router that is used by links if no <code>router</code> property is defined on them. It can either be an object or a function. JointJS provides a collection of <a href="#routers">built-in routers</a> in the <code>joint.routers</code> namespace; alternatively, a <a href="#routers.custom">custom function</a> may be provided. See the <a href="#dia.Link.geometry.router">link geometry router documentation</a> for more information.
